Need help!!

[Crusty]

Yesterday while trying out the new 6x10 SEF coil on the SE I dug this silver 1913 Canada 25 cents from a good 7" deep.....I was really liking the SEF.
It came from ground where the soil is jet black and moist most of the time.
Problem is there seems to be a thin black coating over the coin that just won't come off. The black has flaked off in a few spots including the edges but is stubbornly staying put on most of the surface. My usual method of removing stains with lemon juice isn't working on this one.

I need help!......please.

Dave

 

[John - Maryland]

Old coins will get a "Shell" around them as you described. Put it in White Vinegar and use a wooden tooth pic to remove this shell as it is soaking.

 

[dewcon4414]

Hummm, vinager, ketsup, Bar tenders friend normally wont do much damage to silver.

Dew

 

[Crash620]

Or a more low tech method would be to get yourself a small container, fill it with hot water, and add a quantity of washing soda. Take aluminum foil, fold it up flat, and place it in the bottom of the container, and place your coin on top of the foil. When the reaction stops, remove the coin. Most of the encrustation should have released. If not, brush the coin, much of the material should be loosened. Repeat the process if necessary. DO NOT CLEAN VALUABLE COINS.